Retinal implant with rectified ac powered photodiode

Abstract

The present invention relates to a microelectronics element, such as an optical receiver element, for a medical implant device to be implanted in the human or animal body, particularly for a retinal implant device. The microelectronics element comprises a functional unit including application specific microelectronics, such as a photodiode, for performing a function in the medical implant device, and rectifier means adapted for converting an AC supply voltage into a DC voltage. The DC voltage provided by the rectifier means, or an operating voltage derived from the DC voltage, is configured to be supplied to the functional unit. Further, the functional unit and the rectifier means are integrated on a common semiconductor substrate and configured such that the rectifier means isolates the microelectronics element from application of an external DC supply voltage. The invention also relates to a medical implant device, such as a retinal implant, which incorporates such a microelectronics element.

1 . An optical receiver element comprising:
 a photosensor adapted for detecting incident light, and   a rectifier adapted for converting an AC supply voltage into a DC voltage,   wherein the DC voltage provided by the rectifier, or an operating voltage derived from the DC voltage, is supplied to the photosensor, and   wherein the photosensor and the rectifier are integrated on one common semiconductor substrate.   
     
     
         2 . The optical receiver element according to  claim 1 , wherein the photosensor is adapted for converting a modulated light signal into a corresponding detection signal. 
     
     
         3 . The optical receiver element according to  claim 1 , wherein the photosensor is adapted for receiving and detecting an infrared light signal. 
     
     
         4 . The optical receiver element according  claim 1  wherein the photosensor comprises a photodiode. 
     
     
         5 . The optical receiver element according to  claim 1 , further comprising a capacitor connected to a terminal of the photosensor, wherein the capacitor is adapted for decoupling an alternating component of a detection signal from the terminal of the photosensor. 
     
     
         6 . The optical receiver element according to  claim 1 , further comprising an ambient light control circuit integrated on the common semiconductor substrate and adapted for determining an ambient light intensity. 
     
     
         7 . The optical receiver element according to  claim 6 , wherein the ambient light control circuit is adapted for controlling operation of the photosensor in dependence on the determined ambient light intensity. 
     
     
         8 . The optical receiver element according to  claim 1 , further comprising an amplifier integrated on the common semiconductor substrate and adapted for amplifying a detection signal detected by the photosensor, or a signal derived therefrom. 
     
     
         9 . The optical receiver element according to  claim 8 , wherein the ambient light control circuit comprises an automatic gain control adapted for controlling the amplifier's gain in dependence on the amplitude of the detection signal or the signal derived therefrom. 
     
     
         10 . The optical receiver element according to  claim 9 , wherein the ambient light control circuit is adapted for activating amplification of the detection signal, or of the signal derived therefrom, when ambient light intensity exceeds a predefined threshold.